Fine Structure Research Articles

Comparative Three-Dimensional Fine Structures of the Rabbit Vocal Fold Using Correlative Light and Electron Microscopy.

The comparative fine structures of the rabbit vocal fold (VF) were investigated using the technique combined with correlative light and electron microscopy (CLEM) and transmission electron microscopy (TEM) to elucidate the functional mechanisms. Seven normal New Zealand White Rabbit vocal folds were examined using CLEM technique and TEM to investigate their fine structures. In contrast to the human VF, the rabbit VF lacked the macula flava and vocal ligament. However, the distribution of fibrous components of the lamina propria (LP) of the rabbit VF was similar to the human VF. Spindle-shaped and oval-shaped cells were identified in the LP of the membranous portion of the rabbit VF using CLEM. Furthermore, amorphous materials were produced from vesicles positioned at the periphery of fibroblast cytoplasm. Unlike the human macula flava, stellate cells containing lipid droplets in the cytoplasm were absent in the rabbit VF. The potential utilization of the CLEM technique facilitates the observation of these fine structures in other species commonly employed in animal experiments. Rabbits are considered a suitable species for animal experiments due to the characteristics of the fibrous components of the VF, but it is crucial for researchers to understand the structural and functional distinctions of VF in other species utilized for animal experiments. As the CLEM is a useful technique to evaluate the fine structures of the VF across small species, it is expected to be applied in animal experiments in future studies. NA Laryngoscope, 2025.

Commissioning and operation of 11.74T human MRI magnet for Gachon university gil medical center, South Korea

Abstract Magnetic resonance imaging (MRI) systems with magnetic field strengths higher than 7 Tesla (T), offer exceptional image resolution and signal-to-noise ratio, enabling more detailed visualization of fine anatomical structures, especially for brain, musculoskeletal, and cardiovascular studies. Only a few of them are operating in the whole world. An 11.74 T magnet for human MRI has been commissioned at Gachon University Gil Medical Center (GUGMC) in South Korea in 2022 and has now exceeded two-year operational life at full field. An overview of its features, the commissioning test campaign, and the experience gained after operations is presented.

Mechanical Properties and High-Temperature Steam Oxidation of Cr/CrN Multi-Layers Produced by High-Power Impulse Magnetron Sputtering

In this study, Cr coatings, CrN coatings, and CrN/Cr multi-layer coatings were deposited on the surface of Zr-4 alloy by high-power impulse magnetron sputtering (HiPIMS). We have investigated the effect of coating structure on the microstructure, mechanical properties, and high-temperature steam oxidation properties of coatings. The results show that the single-layer CrN coating has higher hardness but performs poorly in high-temperature steam oxidation compared to the Cr coating due to its greater brittleness, which makes it prone to cracking and spalling in high-temperature steam environments and provides a channel for Zr diffusion. In multi-layer coatings, however, they form a fine columnar crystal structure and a smoother surface, and the more layers there are, the better the mechanical properties and resistance to high-temperature steam oxidation of the coating. In a high-temperature steam environment, the CrN layer decomposes to form Cr2N and N2, and the N atoms diffuse inwards and react with Zr to form an α-Zr(N) layer, which restricts interdiffusion between Cr and Zr and blocks the diffusion of O into the substrate. Therefore, (CrN/Cr)n coatings with a multi-layer structure have excellent high-temperature steam corrosion resistance.

Enhanced Quantum Efficiency in Ca2-2xNaxGdxMgWO6:Mn4+ Phosphors: Allosteric Substitution to Disrupt Local Symmetry for Plant Cultivation Application.

Light-converting films enhance photosynthesis, yet most phosphors' low quantum efficiency restricts their application. This work finds that the co-substitution of Na+ and Gd3+ for Ca2+ in Ca2MgWO6:Mn4+(CMWO: Mn4+) significantly enhances the deep red emission by nearly tenfold. The phosphor can emit red light with a peak at 688nm under near-ultraviolet excitation, and an external quantum efficiency of 51.5%. The luminous intensity of phosphor stored at 85°C and 85% humidity for 1000h is about 95.36% of that at room temperature. Analyses of X-ray Absorption Fine Structure (XAFS), Rietveld, and electron density distribution reveal a unique mechanism of breaking parity-forbidden d-d transitions induced by the symmetry breaking through a big change of Mn4+ d-orbitals distribution under cation substitution. This work designs a unique reflection-typed sunlight-conversion fluorescent membrane using Ca0.8Na0.6Gd0.6MgWO6: Mn4+(CNGMWO: Mn4+), which enables highly efficient directing of deep red toward crops. The actual growth of lettuce and mini-tomatoes is examined, and the fresh weights of lettuce and mini-tomatoes are increased by 57 ± 15% and 30 ± 20%, respectively, compared with the blank control group. Remarkably, the conversion membrane contributes to a +81% increase in thedry weight of lettuce. The results show that the deep red phosphor CNGMWO: Mn4+ holds promise for plant cultivation.

Analysis of the adhesion structure between the cycloolefin polymer and the copper seed layer formed using medium-vacuum sputtering

We have developed a novel approach for the fabrication of 6G communication antenna substrates by directly sputtering a copper seed layer onto a resin with low dielectric properties and low adhesiveness, without relying on a metal adhesion layer such as titanium. This study presents a detailed analysis of the effects of two surface modification methods—vacuum ultraviolet (VUV) irradiation and oxygen plasma treatment—performed before sputtering the copper seed layer on the interfacial structure between a cycloolefin polymer (COP) film and copper plating layer. Using scanning transmission electron microscopy, energy-dispersive x-ray spectroscopy, and selected area electron diffraction, we confirmed that both surface modification methods promote the formation of polycrystalline Cu2O at the interface between the COP film and the copper plating layer. VUV irradiation enhances the smoothness of the COP surface, resulting in the uniform distribution of hydrophilic functional groups. These functional groups stably interact with the sputtered copper, leading to the oxidation of copper during annealing and the formation of a consistent Cu2O layer. In contrast, oxygen plasma treatment selectively etches regions of the COP surface with high oxygen affinity, creating fine structures and concentrating the hydrophilic functional groups in the recessed areas. After sputtering, copper interacts with these localized functional groups, and during annealing, limited diffusion causes the copper to oxidize and aggregates into a Cu2O particle structure. Thus, this study demonstrates that the structures of polycrystalline Cu2O formed at the interface vary depending on the surface modification methods and elucidates the mechanisms behind these differences through analysis of surface morphology and the distribution of functional groups induced by each method.

Application of Convolutional Neural Networks and Rolling Guidance Filter in Image Fusion for Detecting Brain Tumors

Medical image fusion is the technique of integrating images from several medical imaging modalities without causing any distortion or information loss. By preserving every feature in the fused image, it increases the value of medical imaging for the diagnosis and treatment of medical conditions. A novel fusion mechanism for multimodal image data sets is proposed in this paper. Each of the source image is smoothened using cross guided filter in the initial step. Guided filter output is further smoothened to remove fine structures using rolling guidance filter. Then details (high frequency) of each source image are extracted by subtracting the rolling guidance filter output from corresponding source image. These details are fed to convolutional neural networks to obtain decision maps. Finally the source images are fused based on decision map using maximum rule of combination. We assessed the performance of our suggested methodology using several pairs of medical imaging datasets that are accessible to the general public. According to the quantitative evaluation, the recommended fusion strategy for multimodal image fusion improves the average IE by 12.4%, MI by 41.8%, SF by 21.4%, SD by 22.81%, MSSIM by 31.1%, and by 39% when compared to existing methods, which makes it appropriate for use in the medical field for accurate diagnosis.

Isolation, Structure Elucidation and Biological Evaluation of Lomaiviticins F–H, Dimeric Benzofluorene Glycosides from Marine-Derived Micromonospora sp. Bacterium

The discovery of new natural products remains a cornerstone of therapeutic innovation, and effective analytical tools for rapid dereplication can significantly accelerate this process. Using Isotopic Fine Structure (IFS) mass spectrometry, we rapidly identified three new dimeric benzofluorene glycosides, lomaiviticins F–H (1–3), from a marine-derived Micromonospora sp. bacterium. These compounds were isolated and structurally elucidated through advanced spectroscopic techniques, including FT-ICR-MS and NMR. Lomaiviticins F–H exhibit unique structural features, notably the 4-O-methyl-l-angolosamine moieties, which differentiate them from previously known lomaiviticins A–E. The discovery of these compounds highlights distinct biosynthetic linkages within the lomaiviticin family, particularly the C2–C2′ conjoining bonds characteristic of the dimers. Compounds 1–3 were evaluated for in vitro cytotoxicity against a panel of human cancer cell lines; the resulting IC50 values confirmed that the dimeric diazofluorenes of lomaiviticins A and B are critical for anticancer activity. These findings emphasize the utility of IFS in expediting natural product discovery while providing valuable insights into structural and functional characterizations of bioactive compounds.

Pano-GAN: A Deep Generative Model for Panoramic Dental Radiographs

This paper presents the development of a generative adversarial network (GAN) for the generation of synthetic dental panoramic radiographs. While this is an exploratory study, the ultimate aim is to address the scarcity of data in dental research and education. A deep convolutional GAN (DCGAN) with the Wasserstein loss and a gradient penalty (WGAN-GP) was trained on a dataset of 2322 radiographs of varying quality. The focus of this study was on the dentoalveolar part of the radiographs; other structures were cropped out. Significant data cleaning and preprocessing were conducted to standardize the input formats while maintaining anatomical variability. Four candidate models were identified by varying the critic iterations, number of features and the use of denoising prior to training. To assess the quality of the generated images, a clinical expert evaluated a set of generated synthetic radiographs using a ranking system based on visibility and realism, with scores ranging from 1 (very poor) to 5 (excellent). It was found that most generated radiographs showed moderate depictions of dentoalveolar anatomical structures, although they were considerably impaired by artifacts. The mean evaluation scores showed a trade-off between the model trained on non-denoised data, which showed the highest subjective quality for finer structures, such as the mandibular canal and trabecular bone, and one of the models trained on denoised data, which offered better overall image quality, especially in terms of clarity and sharpness and overall realism. These outcomes serve as a foundation for further research into GAN architectures for dental imaging applications.

Measuring phase difference to sense small-scale ocean sound-speed structure.

Observations from a broadband acoustic experiment in deep water probe the temporal behavior of mid-frequency propagation through sound-speed fine structure advected by internal waves. The measured phases of two arrivals with similar propagation paths at 1.8 km range are sampled every 63.5 ms for 30 min. Simultaneous measurements of ocean fine structure near the propagation are used to model the changing arrival phase. The phase difference between arrivals is analyzed to understand changes in the underwater acoustic channel at the meter scale. A comparison between modeled and observed phase difference highlights an internal wave driven signal in the acoustic observations.

Effects of Wx, SSIIa and FLO2 alleles and their interactions on the formation of multi-scale structures of rice starch.

The multi-scale structures of rice starches from 16 recombinant inbred lines and their parents with different combinations of Wx, SSIIa and FLO2 alleles were investigated. Results indicated that the starch multi-scale structures were significantly affected by genotype, environment and genotype × environment interaction. Wx, SSIIa and FLO2 alleles and their interactions significantly affected the starch fine structure. Starches with Wxa allele had higher amylose content (AC) in different amylose chain regions (hAm,i~iii), degree of polymerization (DP) of amylose peak (XAm), Bragg long period distance (dac), but lower relative crystallinity (RC) compared with Wxb. The starches with SSIIaGC allele had higher XAm, more amylopectin B1 chains (fb1) and RC, but less A chains (fa) and dac than those of SSIIaTT. The floury2 (flo2) mutant starch displayed increased ratio of the peak heights of amylopectin (hAP2/hAP1), fb2 and dac, but decreased RC compared to the wildtype. The Wx × SSIIa interaction had a significant impact on AC, XAP1, βAm,iii, average chain length of amylopectin molecules (X¯) and RC. The interaction effects of FLO2 × Wx were significant for AC, hAm/hAp1, hAm,ii, βAm,iii, hAm,iii, RC, D and dac. Significant FLO2 × SSIIa interaction was detected for XAM, hAP2/hAP1, βAm,ii, fb1, fb3 and RC. FLO2 × Wx×SSIIa effect was significant for XAP1, hAP2/hAP1, βAm,ii, fa, fb3 and X¯. This study will help us to further understand the individual and interaction effects of the Wx, SSIIa and FLO2 and the effect of environments on the starch fine structure, but also promote high-quality rice breeding through structural modification of starch.

Full disc [C II] mapping of nearby star-forming galaxies

Context. As a major cooling line of interstellar gas, the far-infrared 158 μm line from singly ionised carbon [C II] is an important tracer of various components of the interstellar medium in galaxies across all spatial and morphological scales. Yet, there is still not a strong constraint on the origins of [C II] emission. Aims. In this work, we derive the resolved [C II] star formation rate relation and aim to unravel the complexity of the origin of [C II]. Methods. We used the Field-Imaging Far-Infrared Line Spectrometer on board the Stratospheric Observatory for Infrared Astronomy to map [C II] in three nearby star-forming galaxies at sub-kiloparsec scales, namely, NGC 3627, NGC 4321, and NGC 6946, and we compared these [C II] observations to the galactic properties derived from complementary data from the literature. Results. We find that the relationship between the [C II] fine structure line and star formation rate shows variations between the galaxies as well as between different environments within each galaxy. Conclusions. Our results show that the use of [C II] as a tracer for star formation is much more tangled than has previously been suggested within the extragalactic literature, which typically focuses on small regions of galaxies and/or uses large-aperture sampling of many different physical environments. As found within resolved observations of the Milky Way, the picture obtained from [C II] observations is complicated by its local interstellar medium conditions. Future studies will require a larger sample and additional observational tracers, obtained on spatial scales within galaxies, in order to accurately disentangle the origin of [C II] and calibrate its use as a star formation tracer.

Noise-matched total-likelihood-based bilateral filter: Experimental feasibility in a benchtop photon-counting CBCT system.

Material decomposition induces substantial noise in basis images and their synthesized computed tomography (CT) images. A likelihood-based bilateral filter was previously developed as a neighborhood filter that effectively reduces noise. However, this method is sensitive to image contrast, and the noise texture needs improvement. It is also necessary to address how to optimally combine filtered basis images to synthesize CT images. This study addressed these issues by introducing total likelihood and a noise-matched condition. The experimental feasibility of the proposed method was demonstrated in a benchtop photon-counting CT (PCCT) system using the following steps: (1) A calibration process for forward modeling, (2) maximum likelihood (ML)-based material decomposition, which is accurate but suffers from substantial noise, (3) noise reduction by applying a total-likelihood-based filter, and (4) CT image synthesis using the noise-matched condition. The proposed method was compared with conventional neighborhood filters and statistical iterative reconstruction with edge-preserving regularization. The local noise and task-based modulation transfer function (TTF) were analyzed using a test phantom, and the proposed method was found to preserve the spatial resolution better than the other methods, especially in low-contrast regions. In the chicken leg experiment, the proposed method improved the fine structures and background textures in the denoised images and exhibited superior properties in analyzing the noise power spectrum. The proposed method is effective and computationally efficient for noise reduction in PCCT and can potentially replace conventional iterative edge-preserved regularization approaches.

Studies on Polyvinyl Pyrrolidone (PVP) and Tapioca-Based Polymer Nanocomposites for Solid Polymer Electrolyte Applications in Batteries

Blending polymers has wide applications in batteries, since it possess different physical and chemical properties. In this study blending of PVP/tapioca and PVP/tapioca/polyamide have been prepared and characterized. The compatibility or miscibility of the polymers at the molecular level determines the new properties of the polymer blends. The synthesised polymer blends were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Spectroscopy (UV-Vis) and Atomic Force Microscopy (AFM). Acoustical and excess parameters were studied for blends of PVP/tapioca and PVP/tapioca/polyamide in organic solids. By measuring ultrasonic velocity and adiabatic compressibility, the excess parameters were used to determine the nature of polymer interactions in the solvent.The topographical images are shown small particles approximately 50 nm in size, medium particles 100 nm in size, and large particles 175 nm in size were all observed. All particles exhibited a lobed-type fine structure; for the 175 nm sized particles, the lobes were 50 nm – 175 nm in size and appeared evenly distributed around the center of the particles.

Microbial changes, including methanogens, influenced by arsenic speciation in anaerobic wetland environments.

Methylated and inorganic arsenic species are frequently detected in natural water systems due to anthropogenic activities and geological origins. However, the impact of arsenic species on microbial activity, particularly on methanogens responsible for methane production, remains underexplored. This study investigates the effects of arsenic on methanogenesis by adding iAs(V) and DMA(V) to wetland sediment batches and monitoring arsenic speciation in the supernatant and methane production over time. Changes in arsenic behavior in the sediment were analyzed using X-ray Absorption Fine Structure (XAFS). Microbial diversity analysis revealed that while iAs(V) acted as an electron acceptor and its reduction to iAs(III) inhibited methanogen activity due to its toxicity, DMA showed minimal effects on methane production. These findings demonstrate that arsenic dynamics in wetlands influence methane-producing microorganisms, with inorganic form of arsenic species posing significant inhibitory effects, whereas less toxic DMA(V) appears to have limited impact. This might shed light on the potential for regulating methane emissions in arsenic-contaminated wetlands.

Quasi-Monte Carlo methods for mixture distributions and approximated distributions via piecewise linear interpolation

We study numerical integration over bounded regions in Rs, s≥1, with respect to some probability measure. We replace random sampling with quasi-Monte Carlo methods, where the underlying point set is derived from deterministic constructions which aim to fill the space more evenly than random points. Ordinarily, such quasi-Monte Carlo point sets are designed for the uniform measure, and the theory only works for product measures when a coordinate-wise transformation is applied. Going beyond this setting, we first consider the case where the target density is a mixture distribution where each term in the mixture comes from a product distribution. Next, we consider target densities which can be approximated with such mixture distributions. In order to be able to use an approximation of the target density, we require the approximation to be a sum of coordinate-wise products and that the approximation is positive everywhere (so that they can be re-scaled to probability density functions). We use tensor product hat function approximations for this purpose here, since a hat function approximation of a positive function is itself positive. We also study more complex algorithms, where we first approximate the target density with a general Gaussian mixture distribution and approximate this mixture distribution with an adaptive hat function approximation on rotated intervals. The Gaussian mixture approximation allows us (at least to some degree) to locate the essential parts of the target density, whereas the adaptive hat function approximation allows us to approximate the finer structure of the target density. We prove convergence rates for each of the integration techniques based on quasi-Monte Carlo sampling for integrands with bounded partial mixed derivatives. The employed algorithms are based on digital (t, s)-sequences over the finite field F2 and an inversion method. Numerical examples illustrate the performance of the algorithms for some target densities and integrands.

Ubiquitous Small-scale Extreme-ultraviolet Upflow-like Events above Network Regions Observed by the Solar Orbiter/Extreme Ultraviolet Imager

Abstract Universal small-scale solar activity in the quiet region is suggested to be a potential source of solar wind and the upper solar atmosphere. Here, with the high-resolution 174 Å imaging observations from the Solar Orbiter/Extreme Ultraviolet Imager, we investigate 59 EUV upflow-like events observed in the quiet Sun. Their average apparent (plane-of-sky) velocity, lifetime, and propagation distance are measured as 62 km s−1, 68.6 s, and 3.94 Mm, respectively. These upflow-like events exhibit dynamic characteristics but lack base brightening, featuring a hot front and subsequent cold plasma ejection. A total of 39% of the EUV upflow-like events exhibit recurrent characteristics. Unprecedented high-resolution 174 Å observations reveal that some EUV upflow-like events exhibit blob-like fine structures and multistrand evolutionary features, and some upflow-like events can cause localized haze-like plasma heating ahead of their spire region during the ejection process. A subset of the EUV upflow-like events covered by the Solar Dynamics Observatory reveals that they appear at the chromospheric networks. Through emission measure analysis, we found that these upflow-like events eject hot plasma of transient region or coronal temperature (an average of ~105.5 K). We suggest that EUV upflow-like events may be EUV counterparts of chromospheric spicules and/or transition region network jets and play a role in heating the localized corona above the network regions.

Stress State and Fatigue Life Assessment of the Bolts at the Outlet End of Fracturing Pump

The fracturing pump serves as a critical piece of equipment in enhancing oil and gas recovery rates. However, under the coupled action of high-pressure fluid pulsation circulation in the pump body and the vibration of fracturing equipment, the bolts connecting the fracturing pump and fracturing manifold flange are prone to fatigue failure. In this paper, a three-dimensional finite-element model of the threaded bolt connection structure at the fracturing pump outlet end with a fine thread structure was established, and the measured vibrational displacement of the fracturing pump under different driven modes was used as the load to obtain the internal stress state of the full-thread bolt and the double-headed bolt used in the fracturing operation site. Based on the stress state, the fatigue life of the two types of bolts under various loading conditions was then simulated using the Brown—Miller fatigue damage criterion. The results indicate that for bolts of the same structural type, the maximum stress and stress variation amplitude increase in the sequence of the diesel-driven, single-motor-driven, and dual-motor-driven methods. Additionally, under the same load, the stress of the full-thread bolt is lower than that of double-headed bolt. The fatigue life analysis results show that under the vibrational load of diesel drive, the full-thread bolt can obtain a longer fatigue life of approximately 2042.89 h. However, under the load of dual-motor-driven method, the fatigue life of double-headed bolt is the lowest, only 717.46 h. A comparison with the fatigue life of bolts in actual engineering projects indicates that the predicted fatigue life of the bolts is consistent with the actual service life, which can provide effective guidance for the inspection and maintenance of fracturing pump equipment.

Aging-Induced Microstructural and Property Changes in Direct Laser Energy Deposited NiCrFeSiBC Hardfacing Alloy Bushes

Abstract Wear resistant NiCrFeSiBC hardfacing alloy bushes for fast breeder reactor applications are fabricated through direct laser energy deposition (DLED) using CO2 laser with optimized parameters for laser power (2.5 kW), scan speed (4.2 mm/s), powder feed rate (4 g/min) and 60% of track to track overlap. DLED bushes have significantly different microstructure than weld deposited ones. As-deposited bushes have predominantly uniform fine dendritic solidification structure of γ-Ni + Ni3B, γ-Ni + Ni3B + Cr3C2 and Ni-B-Si eutectics with low volume fractions of Cr-rich borides and carbides. Microstructural heterogeneity is observed only in layer overlap regions characterized by coarsening of carbides that resulted in lower hardness (625 ± 11 HV0.1) compared to layer interiors (740 ± 19 HV0.1). Effect of aging at 550 °C on the microstructure and properties of the bushes is investigated using experimental and thermo-kinetic simulation techniques. Microstructure of the bushes remains stable without significant coarsening of the γ-Ni + Ni3B eutectic structures even after heat treatment for 4000 h. However, precipitation and coarsening behavior of Cr7C3 and Cr23C6 carbides are affected by aging which is reflected in the variation in hardness. Hardness of the bushes increases up to 100 h of aging due to the precipitation of fine Cr-rich carbides, and with increase in the duration of aging, carbides coarsen thereby reducing the hardness. Based on the study, it is concluded that direct laser energy deposited bushes may have better stability with respect to microstructure and properties at service temperatures.

Super-Resolution Mitochondrial Fluorescent Probe for Accurate Monitoring of Drug-Induced Liver Injury.

Drug-induced liver injury (DILI) has emerged as an urgent clinical challenge. It is characterized by mitochondrial dysfunction in liver cells, which leads to abnormal changes in H2O2 levels within the mitochondria. Super-resolution imaging allows for the observation of the fine structure of mitochondria at the nanometer scale, potentially enabling the detection of mitochondrial H2O2 levels during DILI at the subcellular organelle level. Here, we report the design and synthesis of a novel H2O2-activated probe for the detection of mitochondrial H2O2 levels. SML is a near-infrared (NIR) fluorescent probe with a large Stokes shift (260 nm) and a sensing mechanism based on intramolecular charge transfer (ICT) switching. Super-resolution imaging of mitochondrial H2O2 was conducted using structured illumination microscopy (SIM). The improved accuracy in observing periods of mitochondrial dysfunction allows the SML probe to be effectively utilized for the rapid monitoring nanoscale upregulation of H2O2 during DILI and hepatic fibrosis, thus providing SML with the capability to screen for effective therapeutic candidates.

High-resolution microscopy of biofilm and bacteria on titanium implants

Abstract Implant-associated spine infection (IASI) is related to bacteria and the formation of biofilm. Numerous analyses on the formation mechanism of biofilm have been reported based on in vitro studies. However, the available literature is lacking detailed high-resolution characterization of biofilms on surgically removed implants. The present work deals with the development of a simplified fixation protocol applied on ex-situ Ti-6Al-4V implants. High-resolution scanning electron microscopy was applied for detailed characterization of various types of bacteria as well as biofilm structures. Erythrocytes and Staphylococci as well as fibrin networks were observed on implants removed from different patients. Moreover, the application of the new fixation protocol together with high-resolution microscopy revealed fully developed biofilms totally covering the bacteria as well as very fine structures attaching the bacteria to the implant surfaces, corresponding to early stages of biofilm formation.